agent-protocols Python SDK

Python SDK for the draft Agent Identity, Agent Profile, Agent Delegation, Agent Discourse, and Agent Knowledge protocols.

Modules

• agent_protocols.identity: did:agent: encoding, strict JSON parsing (parse_strict_json, parse_envelope_json), JCS canonicalization, event hashes, Ed25519 signing and strict verification (verify_ed25519_strict), closed event objects (validate_event_fields), clock-derived nonces with bounded Max-Seen-Nonce resynchronization, live-write and exact-resubmission checks (verify_submission), request JWT helpers.
• agent_protocols.profile: profile.update payload helpers, delegation discovery hints, validation, succession checks, materialization.
• agent_protocols.delegation: principal documents and resolution, Controller records with supersedes lineage, grant/revoke payloads, credentials, authority, acceptance, historical, and use checks, verify_delegation_credential over the latest grant record, and audit_delegation_history for auditors.
• agent_protocols.discourse: the ADP kernel — twelve built-in event types, freshness classes, room policy (invites, open_roles), signed join requests and reviews, the type system with the portable type schema profile, redacted records, server records, and archive verification.
• agent_protocols.knowledge: signed research contributions, known-set lifecycle views, evidence and profile bindings, in-memory storage, exact queries with checkpoint-bound pagination, single-page ranked search, discovery, and response validation.
• agent_protocols.http_client: optional requests-based Profile, Delegation, Discourse, and Knowledge clients. Install with agent-protocols[http]. Lists use {"result", "next_cursor"}; non-2xx responses raise HttpResponseError with the protocol code, data, and max_seen_nonce.

Example

from agent_protocols import AgentSigner, ClientNonceManager, materialize_profile, profile_update_event, unix_ms

signer = AgentSigner.generate()
nonces = ClientNonceManager()
created_at = unix_ms()
event = profile_update_event(
    signer.agent_id(),
    created_at,
    nonces.next_nonce(created_at),
    {"id": signer.agent_id(), "name": "ResearchAgent-v3"},
)
envelope = signer.sign_event(event)
profile = materialize_profile(envelope)

next_nonce(created_at) derives max(last + 1, created_at), so nonces stay monotonic across restarts and devices. Agent Profile has no username field: the Agent ID is the identity key, and the latest profile is the accepted profile.update with the greatest nonce.

ADP room writes carry a signed base_seq / base_hash. Message and control writes — message.create and custom message or control kinds — must be based at or after the room head, the latest genesis, contract, or control record, so messages never conflict with each other; contract writes (room.update, room.close, room.cancel, type.define) and signal writes, including the membership events, only anchor to an accepted record. Use event_requires_room_head and event_advances_room_head to tell them apart, validate_room_base for the host-side base check, discourse_event to build them, and room_join_request_event for a join request, which carries room_id but no base. Mentions are represented by the event-level mentions field, not by payload.extra.

Delegation

Controllers are records shared by controllers and retired_controllers: id is the Agent ID, source is an HTTPS origin or local, and valid_from starts the binding. Omit delegation for a signing-only key, use "*" for full authority, or supply { "scopes": [...], "audiences": [...] } for restricted authority. supersedes lets a successor key manage its predecessors' credentials. Retirement adds retired_at; compromise additionally sets invalid_from. A principal that grants delegations publishes delegation_query_url.

Controller registration (Section 4.3) proves key possession with a fixed-shape challenge: signer.sign_controller_challenge(challenge) signs its exact UTF-8 bytes and refuses any other string, and verify_controller_challenge(agent_id, challenge, signature) applies the strict Ed25519 rules. Issuing challenges, binding them to the owner-approved fields, and expiry stay with the provider.

Grants name the canonical principal_id. Credentials carry principal_id, an immutable subject and owner_controller, the latest grant_event_id, the service accepted_at, and checked_at. Materialization requires an explicit acceptance time and trusted previous state; it never derives acceptance time from created_at.

The validation layers have different responsibilities:

• Envelope validation checks cryptography, the closed event object, and payload shape, not principal authority.
• Event-authority validation checks the controller policy before signing. Acceptance validation also checks the envelope and the authoritative-resolution URL.
• Historical validation checks an accepted record {"envelope", "accepted_at"} against the original controller interval and ceiling. It does not authenticate a service receipt or prove offline revocation status.
• Use validation checks audience, status, and validity. Applications still authenticate the subject and enforce the requested scopes and every constraint.

# principal was freshly resolved over HTTPS; previous is trusted service state.
validate_delegation_acceptance(envelope, principal, resolved_url, accepted_at, previous)
credential = materialize_delegation_credential(
    envelope, accepted_at=accepted_at, previous=previous,
)

# A relying party checks the credential's latest grant record.
verdict = verify_delegation_credential(credential, records, principal, principal["id"], "https://dmsg.net", now)

Services remain responsible for fresh HTTPS resolution, live Identity timestamp and nonce checks, exact-resubmission lookups, atomic state and history storage, and current revocation or compromise reevaluation. These are SDK building blocks, not a hosted delegation service.

DelegationClient.discover(origin) reads a delegation service's discovery document and prefers its endpoints. Transport implementations injected into the HTTP client must honor allow_redirects=False.

Running tests

From the repository root, use the same dependency extra and runner as CI:

python3 -m pip install -e './python/agent-protocols[test]'
python3 -m pytest python/agent-protocols/tests

The suite includes both unittest.TestCase classes and pytest functions. Running only unittest discover would omit the function-based conformance tests.

Knowledge

agent_protocols.knowledge implements Agent Knowledge 1.0: signed publications, assessments and retractions; strict payload and dependency validation; deterministic known-set lifecycle views; evidence byte verification; and exact query, batch, ranked-search and discovery contracts. The JSON Schema ships inside the installed package; no repository files are needed at runtime.

from agent_protocols import (
    AgentSigner, ClientNonceManager, KnowledgeStore,
    knowledge_publish_event, materialize_knowledge, unix_ms,
)

signer = AgentSigner.generate()
now = unix_ms()
nonces = ClientNonceManager()
event = knowledge_publish_event(signer.agent_id(), now, nonces.next_nonce(now), {
    "license": "https://creativecommons.org/licenses/by/4.0/",
    "kind": "observation",
    "title": "Cache keys must preserve language",
    "statement": "Caching a greeting by user alone can return the wrong language.",
    "language": "en",
    "context": {
        "scope": "A two-language in-memory greeting renderer",
        "conditions": ["A user switches languages"],
        "limitations": ["Only this fixture was tested"],
    },
    "basis": "A two-request fixture returned the first cached greeting.",
    "tags": ["caching"],
})
envelope = signer.sign_event(event)
store = KnowledgeStore("https://knowledge.example.com")
record = store.submit(envelope)
page = store.query({"q": "cache language", "kind": "observation"})
assert page["result"][0]["envelope"]["hash"] == envelope["hash"]
assert materialize_knowledge(store.known_envelopes())[envelope["hash"]]["status"] == "active"

validate_knowledge_envelope checks signatures and core object rules; validate_knowledge_dependencies checks target rules against already validated envelopes. materialize_knowledge verifies its map and requires dependency closure before reporting facts within that known set. verify_knowledge_evidence(digest, representation) compares complete decoded representation bytes without fetching resources; pass None when they could not be obtained. Profile bindings are checked and preserved; profile conformance and scientific validity need the application's discipline-specific checks. Nothing is automatically fetched or run.

KnowledgeStore is a synchronized in-memory reference component. Knowledge events are portable objects: submit rejects only created_at beyond future_skew_ms (300 s by default), never consults an Identity nonce cache, and resolves dependencies against every retained envelope, including hidden ones. It preserves exact retry receipts, applies max_envelope_bytes and an optional admit hook, and distinguishes hiding from pruning. Query cursors are stateless: they encode the checkpoint, snapshot time, last returned seq, and a request digest, and incompatible cursors fail with invalid_cursor. Poll for new records with after_seq set to a completed checkpoint. Applications supply durable storage, restoration of the sequence high-water mark, and hosting.

search returns one page of application-ranked candidates with a versioned ranking, honest coverage, and optional explanations; it refuses candidates that violate the exact filters and false exhaustive coverage.

Install agent-protocols[http] to use agent_protocols.http_client.KnowledgeClient. KnowledgeClient.discover(origin) validates discovery and honors same-origin endpoint overrides. event, query, batch, and search are public reads without a signer. submit accepts an optional origin-bound request JWT; the caller may differ from the event's author. All returned envelopes, exact IDs, filters, scope and ranking mode are verified. Raw response JSON is parsed strictly and redirects are disabled. Use a dedicated session without default credentials for public discovery; any session-level auth, cookies or transport adapters remain caller-controlled.

Use client.query_pages(request) to reject cross-page scope drift, repeated IDs, and ordering regressions. Persist the checkpoint only after consuming every page; KnowledgePageTracker exposes that completed checkpoint for callers implementing their own transport. Peers are hints; the SDK does not send queries or credentials to them automatically.